1. Field of the Invention
The present invention relates to a hole punch, and more specifically, to a punch for making a plurality of holes in a medium such as paper.
2. Description of the Prior Art
Hole punches are common devices found in offices, schools, and homes. Hole punches serve to punch or cut holes into one or more sheets of paper. The result is that the punched paper can then be stored in a binder or bound by some other means.
The working principle of the common three hole punch is straightforward. A lever arm is hinged to a base, and three hole punch heads are connected to the lever arm. When a user presses down on the lever, the three hold punch heads are driven into receptacles in the base thereby cutting holes into paper placed on the base. Such a hole punch is suitable for light use; since the holes are punched simultaneously and by human effort, this type of punch is limited in the number of holes and in the number of sheets of paper that can be punched.
One notable improvement in the basic hole punch is taught by Mori in U.S. Pat. No. 5,463,922, which is included herein by reference. Mori's punch is capable of cutting a large number of holes into several sheets of paper. Briefly, referring to FIG. 1, a slide rail 11 has a multiplicity of pairs of first slots 15. Each pair of first slots 15 is provided for supporting an actuator pin 13 for actuating a cutting tool 17. A slider 14 is fitted on the slide rail 11 and is slidable along it to engage the actuator pins 13 and thereby lower the cutting tools one after another to make a line of holes in paper. The slider 14 has an arch-shaped cross section to fit slidably over the slide rail 11 and has an inner surface provided with an upper guide surface 143 and a lower guide surface 144 which define a guide groove in which the actuator pins 13 are engageable to move the cutting tools 17 vertically. When the slider 14 is slid along the rail 11, the guide surfaces 143, 144 move the actuator pins 13 driving the cutting tools down and up.
While Mori's hole punch is one solution of how to cut a large number of holes into several sheets of paper, it suffers from several drawbacks. First, for each hole to be cut, there is one moving cutting tool 17. Thus for 30 holes, at least 30 separate moving parts are required, and with each moving part comes the risk of malfunction. Second, the actuator pins 13 are required to be small diameter, and are thus prone to breakage or to damaging the guide surfaces 143, 144. Given these two drawbacks, and more may be apparent to a skilled designer or user, there is a need for an improved hole punch.